During the mid-1950's, as Willibald Jentschke received a call from the University of Hamburg, he coupled his acceptance of a teaching chair in physics with the possibility of research with a modern particle accelerator. Jentschke was particularly interested in establishing a basis for the study of elementary particle physics in Germany. His goal was the performance of internationally-recognized research which would also provide students with up-to-date training. The result, in 1959, was the foundation of the Deutsche Elektronen-Synchrotron DESY, a national research center, funded by the Federal Republic and the City of Hamburg. Jentschke was quickly successful in interesting important international scientists in collaborating at DESY, and thus lying the foundation for the international nature of activity at the institute. Currently, 3400 scientists from 35 countries are involved in research at DESY. From 1959 until the end of 1970, Prof. Jentschke was chairman of the DESY Board of Directors, as well as being Director of the 2nd Institute for Experimental Physics of the University of Hamburg for many years. His efforts in these two posts established the strong connections between the Faculty of Physics at the University of Hamburg and DESY. These connections were always intensified, and one of the results is the Institute of Laser Physics moving to the DESY site.

DESY's history is inseparably connected with Willibald Jentschke. From the very beginning, making DESY into an internationally-competitive institute was a special concern of his - and one in which he was doubly successful: in 1964 he was able to inaugurate the electron synchrotron "DESY"-DESY's first accelerator for research into particle physics. During the following years, he set in motion plans for an electron-positron storage ring, which went into operation in 1974 under the name "DORIS". In addition, the possibilities for the scientific use of synchrotron radiation were also investigated at DESY right from the start. These studies led to a symbiosis-which has come to be characteristic of DESY-between elementary particle physics as pure basic research and applications-oriented investigations in natural sciences and technology utilizing synchrotron radiation. This symbiosis finds its continuation in DESY's project for the future, the 33-kilometer-long linear accelerator TESLA with integrated X-ray lasers.

The origins of Jentschke's success lie not only in his scientific competence-he carried out research on nuclear-physical processes at the Universities of Vienna and Illinois (USA)-but also in his warm-hearted and motivating leadership style. Once he said that he wanted a team, and those who would not fit in were of no use to him. This remark is characteristic for Jentschke's distinct team spirit.

Starting in 1971, Professor Jentschke headed the European Laboratory for Particle Physics CERN near Geneva for five years. In the last years before his retirement, he once again devoted himself entirely to research and teaching at the University of Hamburg and remained actively involved in DESY and science till his death.